Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks

From	Christoph Lameter <cl@linux.com>
Newsgroups	linux.kernel
Subject	Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks
Date	2016-02-04 04:30 +0100
Message-ID	<qYiMh-31h-5@gated-at.bofh.it> (permalink)
References	(2 earlier) <qYaF6-5Ec-51@gated-at.bofh.it> <qYcQz-7bF-19@gated-at.bofh.it> <qYdjA-7nl-11@gated-at.bofh.it> <qYeIH-fd-35@gated-at.bofh.it> <qYghr-1kT-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, 3 Feb 2016, Laura Abbott wrote:

> I also notice that __CMPXCHG_DOUBLE is turned off when the debug
> options are turned on. I don't see any details about why. What's
> the reason for turning it off when the debug options are enabled?

Because operations on the object need to be locked out while the debug
code is running. Otherwise concurrent operations from other processors
could lead to weird object states. The object needs to be stable for
debug checks. Poisoning and the related checks need that otherwise you
will get sporadic false positives.

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Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks Laura Abbott <labbott@redhat.com> - 2016-02-03 19:50 +0100
  Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks Kees Cook <keescook@chromium.org> - 2016-02-03 22:10 +0100
    Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks Laura Abbott <labbott@redhat.com> - 2016-02-03 22:40 +0100
      Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks Christoph Lameter <cl@linux.com> - 2016-02-04 00:10 +0100
        Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks Laura Abbott <labbott@redhat.com> - 2016-02-04 01:50 +0100
          Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks Christoph Lameter <cl@linux.com> - 2016-02-04 04:30 +0100

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